3. .NET Gadgeteer
.NET Gadgeteer platform definitions take NETMF's flexibility to the next level. It is a set of rules on how hardware modules can interact with a mainboard. The complete specifications and software are open-source. GHI Electronics is proud to the first to offer a .NET Gadgeteer platform.
More details are found at http://www.ghielectronics.com/products/dotnet-gadgeteer
This book is not meant to be used for Gadgeteer devices but it is a great tool to understanding NETMF, which is Gadgeteer's core engine.